Electric-lamp socket.



G. B. THOMAS.

ELECTRIC LAMP SOC'YKBT.

APPLICATION FILED JAN. 11. 1911.

987,414, Patented Mar. 21, 1911.,

I 275' Z. V

when sTATns GEORGE B. THOMAS, OF BRIDGEPORT, CONNECTICUL AS SIGNOR TO THE BRYANT ELEC- TRIC COMPANY, OF BRIDGEPORT, CONNECTICUT, A

ELEGTBICLAMP SOCKET.

Specification of Letters Patent.

Patented Mar. 21, 1911.

Application filed January 11, 1911. Serial No. 601,944.

a citizen of the United States of America,

and'residing in the city of Bridgeport, in the county of Fairfield and State of Connecticut, have invented a certain new and Improved Electric-Lamp Socket, of which the following is a specification.

My invention relates to electric lamp sockets and particularly to the type in which a. coil is substituted for the usual threaded shell as the side contact for the lamp base, and the object of my invention is to improve the same in the features hereafter pointed out.

In the accompanying drawings, Figure 1 is a side elevation of a socket of this character in which my invention is embodied and showing a lamp screwed into position; Fig. 2 is a vertical section therethrough on the line 22, Fig. 1; Fig. 3 is a sideelevation similarto Fig. 1 showing the lamp partially removed; and Fig. 4 is a horizontal section on the line M, Fig. 1.

The present socket comprises a casing preferably of insulating material, within which are mountedthe coil side contact B and the center contact C to which the current is led by the wires X and-Y res ectively. When the lamp 'D is screwed into the socket the spirals of the coil D .follow the threaded grooves of the shell E of thelamp base, while the center contact F of the latter engages the center contact 0 of the socket-as usual. The pitch of the coil B is considerably increased by the screwing in of the lamp, and if the lamp is further screwed after the two center contacts have come into engagement, the eifect is to stretch the coil to such an extent that it is permanently distended and its value as a spring grip as well as a side contact lost. Further:

more when the lamp is to be removed the rotation thereof tends to wind the coil so tight on the lamp base that it binds the same and s0 makes the removal of the lamp diflicult as well as increasing the likelihood of injury to the lamp in the process. I now propose to overcome both these difficulties by ofisetting the upper end of the coil to form a lug l0 and oonromrron or connncrrcnr.

providing a recess 11 in the receptacle casing, the sides of which said lug engage with lost motion on either longitudinal or rotary displacement. Thus as the lamp is screwed into the coiland the spirals of the latter are spread, the lug 10 is displaced longitudinally until it engages the upper side act the recess 11. The coil being now held against further distention, all the danger of permanent injury thereto is eliminated, and the function of the coil as a spring grip upon the lamp base insured. Should the lamp be rotated to remove the same, the lug 10 is brought into contact with the side I) of'the recess 11 and the latter forms an abutment which prevents the coil from winding up on the lamp base, thus facilitating the substitution of lamps and eliminating all danger of injury to the same Iclaim as my invention 1. A lamp socket having a recessed casing and a coil Within said casing forming a side contact for a lamp base, said coil having its free end offset to form a lug engaging the recess in the casing with lost motion on either longitudinal or rotary displacement,

substantially as described.

2. A lamp socket having an insulating casing with rectangular recess therein, a coil within said casing forming a side contact for a lamp base, said coil having its free end offset to form a lug engaging the sides of said recess -in the casing with lost motion on either longitudinal or rotary displacement, substantially as described.

In testimony whereof I have signed my name to this specificatiomin the presence of two subscribing witnesses.

GEORGE B. THOMAS.

Witnesses G. W. Goonnrocn, H. M. WICHERT. 

